The coding-synonymous polymorphism rs1045280 (Ser280Ser) in beta-arrestin 2 (ARRB2) gene is associated with tardive dyskinesia in Chinese patients with schizophrenia.

BACKGROUND: Tardive dyskinesia (TD) is a severe and potentially irreversible adverse effect of long-term antipsychotic treatment. Typical antipsychotics are commonly binding to the dopamine receptor D2 (DRD2), but the occurrence of antipsychotic-induced TD is rather delayed; therefore, the development of TD may be associated with mediators or signalling complexes behind DRD2, such as beta-arrestin 2 (ARRB2), an important mediator between DRD2 and serine-threonine protein kinase (AKT) signal cascade. METHODS: A case-control study to evaluate the association between rs1045280 (Ser280Ser) and antipsychotic-induced TD was performed amongst 381 patients (TD/non-TD = 228/153). RESULTS: There was a significant difference in the genotype distribution between TD and non-TD groups (P = 0.025); furthermore, the allelic analysis indicated that patients with T allele had increased risk of TD occurrence (OR(T) = 1.58, 95% CI = 1.14-2.19, P = 0.007). CONCLUSIONS: To the best of our knowledge, this is the first study reporting a positive association between the SNP rs1045280 and TD in schizophrenic patients.

Cytogenetic and molecular characterization of a three-generation family with chromosome 5p terminal deletion.

Terminal or interstitial deletion on the short arm of chromosome 5 is associated with a genetic disorder, cri-du-chat syndrome (cat cry syndrome), which is characterized by a cat-like cry in infancy, facial dysmorphism, microcephaly, and mental retardation. There is a high degree of variation in clinical presentations of patients with cri-du-chat syndrome, which is usually associated with different sizes and locations of deletions in chromosome 5p. Most patients with a 5p deletion have de novo mutations; familial 5p deletion is rare in literature. Here, we report a three-generation family with a 5p terminal deletion. The terminal 5p deletion (5p15.2-pter) in this family was confirmed and characterized by karyotyping analysis, fluorescent in situ hybridization, array comparative genome hybridization, and quantitative polymerase chain reaction. Although the affected family members apparently share deletions of the same size, there are some variations in mental symptoms within this family. Two affected females manifest moderate mental retardation and psychotic symptoms such as delusion of persecution, auditory hallucination, self-talking, and self-laughing, which are rare in cri-du-chat syndrome. In contrast, the other three affected males express mild-to-moderate mental retardation but no psychotic symptoms. Our study suggests that other factors besides the size and location of 5p deletions may modify the mental presentations of patients with 5p deletions.

Association study of polymorphisms in post-synaptic density protein 95 (PSD-95) with schizophrenia.

The postsynaptic density protein 95 (PSD-95) - the prototype of this family - is a modular protein that enables anchoring of NMDA receptors, modulates NMDA receptor sensitivity to glutamate and coordinates NMDA receptor-related intracellular processes. Since hypofunction of NMDA receptors has been implicated in the pathophysiology of schizophrenia, we explored the hypothesis that genetic variants of the PSD-95 gene were associated with a diagnosis of schizophrenia. Three PSD-95 polymorphisms were studied in a sample population of 248 people with schizophrenia and 208 normal controls. One polymorphism (rs373339) was not informative in our Chinese population while the other two polymorphisms (rs2521985 and rs17203281) were analysed with chi-square tests and haplotype analysis. Results demonstrated that the two informative polymorphisms are in strong linkage disequilibrium with each other. Neither single marker nor haplotype analysis revealed an association between variants at the PSD-95 locus and schizophrenia, suggesting that it is unlikely that the PSD-95 polymorphisms investigated play a substantial role in conferring susceptibility to schizophrenia in the Chinese population. Further genetic studies in schizophrenia with other PSD-95-like molecules that interact with the glutamate system are suggested.

Association study of polymorphisms in glycine transporter with schizophrenia.

Glycine acts as an obligatory co-agonist with glutamate on N-methyl-D-aspartate (NMDA) receptors. Brain glycine availability is determined by glycine transporters (GlyT1 or SLC6A9), which mediate glycine reuptake into nerve terminals. Since hypofunction of NMDA receptors has been implicated in the pathophysiology of schizophrenia, this study tests the hypothesis that GlyT1 genetic variants confer susceptibility to schizophrenia. Four GlyT1 polymorphisms were studied in a sample population of 249 people with schizophrenia and 210 normal controls. One polymorphism (rs16831541) was not informative in our Chinese population while the other three polymorphisms (rs1766967, rs2248632 and rs2248253) were analysed with chi-square tests and haplotype analysis. Significant linkage disequilibrium was obtained among the three polymorphisms. Neither single marker nor haplotype analysis revealed an association between variants at the GlyT1 locus and schizophrenia, suggesting that it is unlikely that the GlyT1 polymorphisms investigated play a substantial role in conferring susceptibility to schizophrenia in the Chinese population. Further studies with other GlyT1 variants, relating either to schizophrenia, psychotic symptoms or to therapeutic response in schizophrenia, are suggested.

Association studies of the adenosine A2a receptor (1976T > C) genetic polymorphism in Parkinson's disease and schizophrenia.

Given the implications with respect to the pathogenesis of dopaminergic dysfunction in schizophrenia and Parkinson's disease (PD), as well as the reciprocal antagonistic interactions between adenosine A2a receptor (A2aAR) and the dopamine D2 receptors, A2aAR may be a candidate gene conferring susceptibility to PD or schizophrenia. In this study, we tested the hypothesis that the A2aAR 1976T > C genetic variant confers susceptibility to or is related to the onset age of schizophrenia or PD using a sample population consisting of 94 PD and 227 schizophrenic patients. We also tested whether the A2aAR 1976T > C relates to antipsychotic-induced tardive dyskinesia in the schizophrenic population. The results demonstrated that in comparing PD patients and controls the distribution of the A2aAR 1976T > C genotypes (P=0.788) and alleles (P=0.702) did not vary significantly. Furthermore, the PD onset age was not significantly different amongst the three A2aAR 1976T > C genotypic groups. In comparing schizophrenic patients and controls, the distribution of the A2aAR genotypes (P=0.330) and alleles (P=0.632) also did not differ significantly. The onset age of schizophrenia and tardive dyskinesia (evaluated with Abnormal Involuntary Movements Scale) were similar within the three A2aAR genotypic groups. Our findings suggest that it is unlikely that the A2aAR 1976T > C polymorphism plays a major role in the pathogenesis of PD, schizophrenia, or antipsychotic-induced tardive dyskinesia in the Chinese population.

Negative association between catechol-O-methyltransferase (COMT) gene Val158Met polymorphism and persistent tardive dyskinesia in schizophrenia.

Chronic administration of typical antipsychotic agents, which mainly act on the dopamine receptors, implicates a role of dopamine system on the susceptibility of tardive dyskinesia (TD). In the present study, the association between a functional Val158Met polymorphism of Catechol-O-methyltransferase (COMT) gene and TD occurrence and TD severity was investigated in 299 Chinese schizophrenic patients with long-term antipsychotic treatment (TD: 166, non-TD: 133). After adjusting the effects of confounding factors, there was no significant association between COMT genotype and TD occurrence (p=0.367). Among TD patients, we found no significant correlation between COMT genotypes and the total scores of abnormal involuntary movement scale (AIMS) (p=0.629). We concluded that this COMT polymorphism might not play a major role in the susceptibility of TD nor on the severity of TD.

Association analysis of a neural nitric oxide synthase gene polymorphism and antipsychotics-induced tardive dyskinesia in Chinese schizophrenic patients.

Recent findings from rodent studies with chronic administration of antipsychotic drugs have indicated the role of neural nitric oxide synthase (NOS1) on the susceptibility of tardive dyskinesia (TD). In the present study, the association between a 3'-untranslated region C267T (3'-UTR C267T) polymorphism of the NOS1 gene and TD as well as TD severity was investigated in 251 Chinese schizophrenic patients with long-term antipsychotic treatment (TD: 128, non-TD: 123). After adjusting the effects of confounding factors, there was no significant association between NOS1 3'-UTR C276T genotypes and TD occurrence (p=0.758). With in the TD group, we could not discover a significant correlation between NOS1 3'-UTR C276T genotypes and the scores of abnormal involuntary movement scale (AIMS) (p=0.219 and 0.774). We concluded that the NOS1 3'-UTR C276T polymorphism might not play a major role in the susceptibility of TD development, or on the severity of TD.

Association between the Ser9Gly polymorphism of the dopamine D3 receptor gene and tardive dyskinesia in Chinese schizophrenic patients.

It has been suggested that dopamine D3 receptor (DRD3) may have important implications for antipsychotic-induced tardive dyskinesia (TD). Previous studies have demonstrated an association between a serine to glycine polymorphism in the first exon of the DRD3 gene and TD; however, the results have been inconsistent. Therefore, we have replicated these studies using a Chinese sample population. A total of 115 schizophrenic patients from chronic wards were assessed for TD severity using the Abnormal Involuntary Movements Scale (AIMS) and were subsequently genotyped for the DRD3 polymorphism. The mean AIMS score for patients carrying the heterozygote (DRD3(ser-gly)) was significantly greater than for those with the homozygotes (DRD3(ser-ser) and DRD3(gly-gly)). Our results are in line with a previous report, the results of which suggest that the presence of the DRD3(ser-gly) genotype may be a risk factor for the development of TD in patients treated with antipsychotics.

Comparative cross-over pharmacokinetic study on two types of postcoital contraceptive tablets containing levonorgestrel.

A pharmaceutical and pharmacokinetic study was carried out on levonorgestrel tablets from two different sources (Hungarian- and Chinese-made). Both preparations contained 0.75 mg levonorgestrel and had been shown to have similar contraceptive efficacy and side effects when used for postcoital contraception. Absorption and bioavailability of the Hungarian-made tablets were greater as evidenced by higher serum concentrations of levonorgestrel, a greater area under the concentration-time curve during the first 24 hours, and a more marked suppressive effect on SHBG levels. These differences most probably reflect differences in their pharmaceutical formulation, in particular the extent of tablet dissolution and the degree of micronisation of levonorgestrel.

[Influence of artificial cycles induced by traditional Chinese medicine on the releasing and reserving gonadotropic hormone function of the pituitary gland in the female with secondary amenorrhea].

Thirty-one patients with secondary amenorrhea, who were grouped, were treated with artificial cycle of traditional Chinese medicine (TCM) and Western medicine. The excitement test for LRH-A of pituitary gland was made pre- and post-treatment respectively. It was suggested that artificial cycle of TCM played positive feedback role in GnH of patients with hypothalamus amenorrhea but negative feedback role in GnH of patients with ovarian semilism, and adjustment role in LH/FSH ratio of patients with PCOS. The results of this study provided scientific basis for clinical application of artificial cycle by TCM.